Watercolor Quilts; Pat Maixner Magaret, Donna Ingram Slusser (Contributor), Barbara Weiland (Editor). This is the classic book on watercolor quilts. It has complete instructions, and many beautiful examples.

Watercolor Impressions; Pat Maxiner Magaret, Donna Ingram Slusser (Contributor). This is the followup book to Watercolor Quilts -- it's a compendium of pictures of watercolor quilts. Don't look for instructions from this one, but it's wonderful for inspiration!

Impressionist Quilts; Gai Perry. This is more art oriented than Watercolor Quilts -- it's an excellent next step. It focuses on fabric and color selection, as well as advanced techniques to create an impressionist masterpiece.

Impressionist Palette : Quilt Color & Design; Gai Perry. The followup book to Impressionist Quilts, this book is great on its own merits. It goes more in depth into the elements of design and color selection, and introduces new techniques and patterns.